Hi Terpfan,
I wasn’t sure but I thought that’s what you meant which is why I posted the link that compared an all latex mattress with a latex/polyfoam hybrid.
Unfortunately there is no way to quantify how long any mattress will last for a specific person or predict exactly when you will decide to replace it because it is no longer suitable or comfortable for you (because this is the only real measure of durability or the useful life of a mattress that really matters) because there are too many unknowns and variables involved that are unique to each person but if a mattress is well inside a suitable comfort/support range and isn’t close to the edge of being too soft when it is new (see post #2 here) and meets the minimum quality/durability specs that are suggested in the guidelines here then it would be reasonable to expect a useful lifetime in the range of 7 - 10 years and with materials that are higher quality and more durable than the minimum guidelines such as latex (in the top comfort layers especially) it would likely be in the higher end of the range or even longer.
There is also much more detailed information about all the many variables that can affect the durability and useful life of a mattress relative to different people in post #4 here and the posts it links to.
One of the additional advantages of a component mattress is that if the comfort layers soften or break down before the deeper layers in a mattress (which is most likely) or if your needs and preferences change down the road you can replace individual layers instead of having to replace the complete mattress.
While I would expect that both mattresses would last most people for 10 years … the odds are probably higher that there will be more “bonus time” after 10 years with an all latex mattress than with a latex/polyfoam hybrid as well.
Phoenix